Recording toll trunk-circuit.



J. E. HILBISH.

RECORDING TOLL TRUNK CIRCUIT.

APPLICATION FILED FEB. e, 1912.

Patented Dec. 1, 1914.

7 H5595 t/ 27 EH'Zb' Z2 Z7 Z Z5 M M/ By M YCSSW Q 15),. fizzbm -'HENORRIS PETERS 60., PHOTO-LITHQ, WASHING rON. D. C.

UNITED STATES PATENT OFFICE.

JOHN E. HILBISH, OF. LA GRANGE, ILLINOIS, A SSIGNOR TO KELLOGGSWITCHBO'ARD AND SUPPLY COMPANY, OF CHICAGO, ILLINOIS, .ACORPORATION OFILLINOIS. V

To all whom itmay concern:

Be it known that I, J on E. HILBIsH, a. citizen of the United States ofAmerica, re-x siding in La Grange, county of Cook, and State ofIllinois, have invented certain new and useful Improvements inRecordingToll Trunk-Circuits, of which the following is a specification.

My invention relates to telephone systems and. has more particularly todo with signal control means for trunk circuits such as are used inconnection with universal cord circuits of a marginal relay type.

An object of my invention is to provide a trunk circuit forinterconnecting a marginal relay cord. circuit and a cord circuit of thesame or different type at a distant operators position, such trunkcircuit having novel signal-control. circuit arrangements for. effectingthe operation of supervlsory S1g nals at the-trunk-circuit anduniversalcord circuit. i

A better understanding of my invention may be had by reference to theaccompanying drawing in which the universal cord circuit A isillustrated and which'may be used for interconnecting lines of differentcharacters such as magneto linesB and common battery linesO. Lines B andC preferably terminate at operators" positions at the same switchboard,such operators positions belng equippedwith universal cord circuits asA,

' for interconnecting these lines, but when a tein illustrated, the lineB has a magneto substation telephone F connected by line connection isdesired between either of the lines as'B and C and linesterminating at adifferent switchboard or different operators position, the trunk circuitD is used for connecting the cord circuit A with a} cord circuit as Eterminating at such'distant or difierent switchboard.

I Referring now more in detail to the sysconductors 1,2, to a linecircuit G- This lineicirouit comprises preferably a line relay LR andcutoff relay CO,-a line sig nal LS and multiple connected jacks J.

The line C which is of a commonbattery type, has a well-known form 'ofcommon battery substation telephone H connected by line conductorsl ,2with a line circuit G composed of apparatus similar to that of linecircuit Grand designated by like reference characters exceptfor theaddition of the suflix prime.xf,The line circuits G and G Specification.of LetterLs Patent.

of the cord circuit.

RECORDING TOLL. TRUNK-CIRCUIT.

signalingby simply varying the connections of theline circuits andconnecting the desired type of substation. The cut-off relays CO and C0are preferably double wound relays, cut-011' relay CO having its twowind- Patented Dec. 1, 1914.. Application filed February 6, 1913. SerialNo.746,462. V

mgs 3, 4, connected in series so as to provide a high resistance paththrough this wmdmg while the windings 3 P, of CO are connected inmultiple so as to provide a comparatively'low resistance path for theoperation thereof. Referring nowtothe universal cord circuit A, itcomprises the talking strands 5, 6,

connecting the plugs? and P plugP being what is known as the answeringplug and plug P the calling plug." A listening key 1 cuits are of coursewell-known and a circuit as shown in a copending application of Chas. A.Simpson Serial No. 723,589, may be used. A pair of supervisory relaysare associated with each end of the cord circuit to be substituted forthe relayMS by the connection is made with a common battery l1ne as C.Three similar relays MS CS and SW are associated with the calling ending supervisory relays and a calling supervisory lamp 8 associated withthe calling supervisory relays. A ringing key RK is provided forconnecting the ringing generator 9 in circuit with the calling plug PThe switching relays SW and SW are preferably of comparatively lowresistance An answering supervlsory lamp 7 1s associated with theanswer- LK is provided and is adaptedto connect an operators testing andconversational telephone (not shown) in circuit with the talking strandof the cord circuit. Such cir- A, the magneto supervisory relay MS beingnormally connected in bridge of the talking strands of the cord circuit,and the common battery supervisoryrelay CS being adapted operation of aswitching relaySW when so that when connection ismade with a line havinga high resistance cut-off relay as CO,

suflicient current does not flow'to energize the switching relay but thecut-oflt'irelay is energized. Thus when the switching relay is notenergized the magnet MS remains in bridge of the circuit. Whenconnection is made with a line having a low resistance path through thecut-01f relay CO suflicient current is allowed to flow through the isequipped with cord circuits as E, and

which for example we will assume is a toll board, the local operator ofthe cord circuit A selects an idle trunk jack 10 at her position andthus extends a connection to a jack 11 before a recording toll operator,who then makes connection with the jack 1.1 by

' means of a cord circuit as E. The recording operator then makes arecord of the number of the calling substation and also the numberof thewanted line and orders the calling subscriber to give a disconnectsignal. At the same time she withdraws the plug 12 ofcircuit E from-jack11 thus operating a disconnect signal 8 at cord circuit A, whereby thelocal operator withdraws plugs P and P The toll operator thus has arecord of the calling and called lines and by means of other circuits(not shown) she may 0011- nect the two lines for conversation. By useofv this arrangement the calling subscriber cannot put through a tollcall unless the correct number of his line is given.

vNow as to the preferred construction of trunk-circuit D, it comprisesmultipleconnected out-going jacks 10 connected by strands 13, 14, toanincoming jack 11 located preferably at a recording tolloperatorsposition. A calling signal relay CSR- is connected to the jack10 so that when connection is made to this jack by a calling plug jPswitching relay SW and relay CSR are connected to the jack 10 so thatwhen connection is made to this jack by a calling plug P switching relaySW andv relay CSR are connected in series, but relay CSR is of com-,iparatively high resistance so as to allow sufficient current to flowthrough relay SW to operate its contacts. But relay CSR is energized bythis circuit to light the calling signal lamp 16 which is associatedwiththe jack 11. A disconnect relay DR is associated with'jack 11 andadapted to be energized when connection is made with said jack by a cordcircuit E, this energization bringing about the energization of an.eifacing relay ,ER which efl'aces the signal 16. When the recordingoperator withdraws plug 12 from a jack 11, the disconnect relay DRdenergizes and places the low'resistance winding 19- in multiple withthe relay CSR so as to providea'low resistance energizing circuit forswitching relay SW and thereby bring about the energization of thedisconnect lamp 8. Y Y

The cord circuit E may be of'any type which may'extend the talkingconductors 13,

and 14 and I have shown a typeada'pt'ed for interconnecting the ordinarymagneto line.

A drop 15 is shown bridgedlacross the strandsof cord E, An operators,telephone connection with a-lineterminating at a distant switchboard andwhich we will assume is a toll line, thesubscriber. operates the hand'generator at the substation in. the

usual mannerlto establish aflow of current and listening key are ofcourse provided but 6 throughthe line relay LK, which may be tracedfronrgroundat normalcontact 20 of relay CO, line conductor 2,,generatorof substation F lineconduct'or. 1, normal contact 21, winding of LB andline signalLS to ground. Relay LR is energized closing its alternatecontacts 22," 23 whereby a locking circuit-for LR is establishedand'line signal LS is lighted by a circuit including alter nate contact22. The-operator. in response to-this signal inserts a plug Pin a jackJ,of the calling line, whereby a circuit for outoff relay. .COfisestablished. including said relayj and switching relay SYV in series.Due to the comparatively high resistance of the winding of COfsaid relaywill energize but suflicient currentdoes not How toener gize switching Yrelay SW. Therefore, the magneto supervisory relay MS has its winding 24maintained in bridge ofthe answering end of the cord circuit; Uponenergization of CO, the circuit for LR is, interrupted andthereforerelay LR denergizes.

interrupting the circuit for -,the,line signal LS. .The operator .nowconnects her telephone set by means, of the listening key 'LK, toascertain the number of the wanted line and finding the wanted line is atoll line terminating; at a different switchboard or operators position,she-tests trunk jacks 10 by means of touching the tip of the plug P tothe sleeve of .thejack in a welleknown' mannerandfinding an idle jackinserts the plug'therein; A circuit isthus established including theswitching. relay SW and the trunk or calling signal relay CSR inseries.Relay CSR is of sufficiently high resistance, to prevent theenergization ofv relay SW but enough current flows through the windingof relay CSR to permit the energization thereof and attraction of itsarmature. Its contact 26.:is-therefore closed establishing a circuit forthe trunk signal .16 traced from battery through said signal116,alternate contact 26 and normalcontact 27 to ground. The recordingoperator before whom the jack 1,1 terminates, inresponse to the lightingoflamp 16, inserts a plug;.12 ofaicord circuit E into jack llttherebyclosingthe contacts -28g-and. establishing ancope'rating circuit fordisconnect. relay DR tracedifroin.

battery through the'fwindingfthereof to f 1 ing toll connections is'ofcourse-common groundat contacts 28. therefore interrupts itsnormal'contact 29 and there-" after closes itsalternate contact 30tooause the operation of effacing relay ER, "Relay ER thereforeinterrupts its normalcontact 27 whereby trunk signal16 is eflaced. Therecording operator now connects her telephone -set to ascertain thenumber of the called line and also the number ofrthe calling line and.then notifies the calling subscriber to hang up and give a disconnectsignalas he will be called later on." I de-.

sire to state that this method of establishpractice but it will beapparent thatthe operator who answers the call at jack 11 may by the useof a cord; circuit as E extend the connection to the wanted. line.Assuming a now that; the calling subscriber is to be calledback infamanner as stated, when the operator tells him to disconnect, he operateshis hand generator,.should itbe a magneto line, to effect the operationof supervisory .signal 7, At this time the-recording operator alsowithdraws the plug 12 from the jack 11 toqbring about the operation ofthe cord supervisory signal 8.

l/Ve will take up the operation of signal 8 first Upon withdrawal ofplug 12 from jack 11, contacts 28 are again interrupted wherebythecircuit :for disconnect'relay DR is interrupted causing itsdeen'ergization' and the closing of its normal contact 29.

" nected in multiple with the relay CSR so through the switching relaySW to cause its"operaftion. 'Th ajt is relay SW attracts its armatureclosing-the alternate contact 3% Y and'the'reby connecting supervisorysignal 8 in circuit W h the ground at normalcontact 35 to cause theoperationof signal 8.

, Now as'to the operation of signal 7,when

the subscriber at the fcalling substation F operates the hand generatorthereat for a disconnect'signal, current flows through the bridgedwinding 24 of relay MS whereby a the said relay isenergi'ze'd closingits alter- This locking circuit is traced from battery through thewinding "31; alternate contact 36, conductor 37 to ground at normal contact88. The closing of this alternate con tact 36 also connects groundthrough normal contact 39 and thereby establishes an -operr atingcircuit for lamp signal7. The operatorat the cord circuit upon observingnections.

thetwo signals 7, S, knows that disconnection is desired, and thereforewithdraws plugs P and P from their respective jacks.

This interrupts the series circuit including relays CO and SW wherebyrelay CO restores, placing the-line B at normal. Relay SW it will beremembered was not energized and therefore said relay remains at normalwhen plug P is withdrawn. Upon withdrawal of plug P the circuitincluding relays SW and SSH is interrupted effecting the restoration ofthese two relays. The

restoration of SW of course interrupts the circuit for'signallamp 8 dueto the interruption of alternate contact34. The supervisory signal 7 isstill lighted so the operator throws the listening key-LK, interruptingthe grounded contact 38 to open the locking circuit for supervisoryrelay MS which restores and lamp is thus extinguished. a g a g g Now asto the restoration of the apparatus of trunk circuitD. Upon saidrestoration of its relay CSR, the locking circuit for relay ER isinterrupted at alternate contact 33 whereby said relay ER restores andrelay DR having restored when plug 12 was withdrawn, trunk circuit D isat normal and available for use in establishing other con In theoperation of the system as just described it was assumed that the callorigi I nated at the magneto substation Now I assuming the calloriginates at the common battery substation H, the supervisory apparatusat the answering end of cordicircuit A operates diflerently, but i thesupervisory apparatusof'theoalling end of the cord cir cuit alwaysoperates the same-when connectlon is made w th atrunk c1rcu1tD,1rrespe'ctive ofthe character of the calling line. that sufiicientcurrent is permitted tofflow The subscriber at substation Hto initiate acall removes his receiver fro'm'its switchhook wherebya circuit isestablished in a well-known way for line relay LR to effeet the lightingof line signal LS The local operator in response tothis signalinthe-cut-otf relay CO both the relays CO a line relay LR and bytheclosing of alternate contact 86 to lock relay MS in its energizedposition, as the current from the" hand generator is for a short periodonly.

nate contacts 20 21 connects the line conductors to the jack. Theenergizationof sertsplug P into a jack J of the calling line i and dueto the low resistance path through i the switching relay SW disconnectsrelay MS and bythe closingof alternate contacts 4:5, i6, connects thecommon battery supervisory relay OS in vbridge of the cord strands. Thereceiver'at substation H be ing off its switch-hook," an energizingcircuit for relay CS. is establishedftraced from bat jtery to the lowerwinding, of CS, alternate contact 46, the sleeve strand ofthe cord and I115 and SWV are energized to attract their armaplug,[out. over the line,returning over the tipv strand' of the plug and cord, alternate contactl5 and the upper winding of OS to ground. Relay CS therefore interruptsits normal contact 4:7 so that the supervisory signal/7 does not light.The operator now finding that a toll call is desired extends theconnection through a trunk circuit D in a manner as previouslydescribed. 7

To elfect disconnection, the subscriber at substation H simply replacesthe receiver upon its switch-hook whereby the circuit for supervisoryrelay CS is interrupted causing the dee nergization thereof and theclosing of ltSllOI'IIliLl contact 47. This establishes a circuit forsignal 7 so that when the other signal 8 is also lighted due towithdrawal of plug 12, the operator withdraws plugs P and P from theirrespective jacks. The withdrawal of plug P efiaces lamp 8 in a manner aspreviously described and the switching relay SW of the answering end ofcord A, having been operated, it restores when the plug P is withdrawn,interrupting its alternate contact 39 and thereby causing theefi'acement of signal 7. The operator 0bserving that the two signals 7and -8 have been effaced by the withdrawal of the plugs does not operatethe key LK. All of the apparatus being at normal once more, it isavailable for use in establishing other connections. j

vThat I claim as new and desire to secure 3 by United States LettersPatent is:

l. .Ajtelephone system comprising a coniiecting circuit, a signal andcontrol relay therefor, a trunk circuit, having out-going andin-coiningterminals, a call signal relay forthe trunk circuit, means forenergizing said call relay upon connection made with the, out-goingterminal by said connecting circuit, a call signal associatedwiththeincoming'terminal operated responsive to said call signal relay, asecond connecting circuit for connecting to the incoming terminal of thetrunk circuit, disconnect and effacing relays operated responsive to thesaid connection for effacing said call signal, said dis- 1 connect relaydeenergizing upon disconnecting the second connecting circuit, and meanseffective upon such deenergization of the disconnect relay to energizesaid control relay at the first connecting circuit and operate its saidassociated signal.

2. A telephone system comprising a connecting circuit, a disconnectsignal and control relaytherefor, a trunk circuit having out-going andincoming terminals, ,a call signal relay for the trunk circuit connectedto the. out-going terminal, means for connecting said relays ii a.series energiz ng circuit upon connection made with said outgoingterminals :by said connecting circuit,

said series circuit being arranged. to allow, energization of the callrelay but not of the man's v control relay, a signal.atftheinconiingter-,

. minal roff the .trunk circuitfoperatedqupon saidenergization'ofthe;callrelay, a second connecting circuit forconnectmgwith the ncoming. terminal of the, trunk circuit, dis-J connect andeffacing relays for the trunk circuit operated responsive to the lastsaid connection whereby said calls gnal 'iseffaced, saiddisconnect relaybeing deenergized upon, disconnecting the lastsaid connecting c rcuitfrom the 1I1COII11Ilg terminal, and

means for Varying thecircuitrelation ofthe.

control and signal relays upondeenergiza tion of the disconnectfrela'ywhereby said outgoing terminals, a series;energizingcircuit for saidswitching and call relays closed upon connectionmade between, the cordcirv cuit and said outgoing terminahsaid series circuit being of suchresistanoeas to allow the operation ofthe callrelay but not that oftheswitching relay, signal at the incoming terminal of the trunk circuitoperated responsive to said operationjof, the call relay, aconnectingcircuit for connecting to the ncomingterminal, vmeans for.effacing said callsignal responsive tothe latter connection, means forvarying the energizing cin cuit of the switching relay responsive to adisconnection of the connectingcircuit from the incoming terminals so asto operate the switching relay, and'means for operating the disconnectsignal of the cord circuit vresponsive to such energization of theswitching relay;

4. A recording. toll operators circuit comprising outgoing andincoming'terminals conductively united, a callv signal f relay connectedwith the outgoingjte'rminal adapted to be energized- -when connectionis; made-thereto, a call signal associated with the incoming terminaland operated responsive to such energizationiof thecall relay,disconnect and efiacing relays, means whereby thesaid relays areenergized when .connece tion is madewith the incoming terminals and thecall signal is eifaced,-.saiddisconnect relaybeing adapted to bedeenergizedavhen disconnection from the incoming terminal is ing theeffective resistance of the circuit ex tendingfrom the outgoing terminalto. a control relay responsive to such deenerg za-' tion of thedisconnect relay.

5. A telephone systemcomprising trunk havingoutgoing and incomingrtermii20 subsequently effected, and means for lowerresponsive to such enerization of the call signal is eifaceol, and means whereby whendisconnection is made fromsaidincoming terminal saiddisconnect relay'isdenergized to'alter the effective resistance of the circuit connectionsextending from the outgoing terminal.

having outgoing and incoming terminals, a

call signal relay adapted to be energized when connection ismadenwiththe outgoing terminal of the trunk circuit, a call signal lighted uponenergization of said call relay,

of two witnesses.

disconnect and efi'acing relays energized when connection is made withthe incoming terminals of the trunk circuit to efface a call signal andwhen disconnection is made from the incoming terminals means areeffected upon the cleenergization of the disconnect relay to lower theresistance of thecall rela to place a low resistance in multiple circuitwith the call signal relay to allow the efiecc a tive operation of theswitching relay of the a 6. A telephone system comprisinga con-" nectingcircuit, a switching relay and a dis-' connect signal therefor, a tolltrunk circuit said. connecting circuit.

Signed by me at Chicago, 1n the county of Cook and State of Illinois, inthe presence JOHN E. HILBISH. Witnesses c G. E. MUELLER, B." OBRIEN.

Copies of this patent maybe obtained for in cents each, by addressingthe Commissioner of ratentl,

. i Washington, I). 0."

